/**
	 * @author Benjamin Zwanzger
	 * @version v1.0
	 * @date 27.03.2013
	 * 
	 */

import java.util.*;

class Stack<Object> extends ArrayList<Object> {
 
 	//Stack stack = new Stack();
	
  
   public boolean isEmpty() {
	 return size() == 0;
  }
  	
   public Object topOf(){
	 return get(size()-1);
  }
  	
   public void push(Object obj) {
	 add(obj);
  }
  	
   public Object pop(){
	 return remove(size()-1);
  }
}
